Vessel with removable sections

ABSTRACT

A vessel comprises a skeleton part carrying propulsion and steering means and comprising a bow section and a stern section connected by a spine and a plurality of container portions engageable with the skeleton part intermediate the bow and stern sections and laterally of the spine, the container portions when engaged with the skeleton part defining therewith the exterior shape of the vessel hull.

ilnite States Patent [1 1 Dragonas et al.

[ Oct. 15, 1974 22 ined;

[ VESSEL WITH REMOVABLE SECTIONS [76] Inventors: Gerasimos NicolaouDragonas, Villa Sevigne, 15 Boulevard de Suisse, Monte Carlo, Monaco;Andrew George Spyrou, Residence Bois Jolie C., Avenue de la Gare, CapDAilob, France 21 Appl. No.: 325,354

[30] Foreign Application Priority Data Jan. 31, 1972 Great Britain4505/72 [52] US. Cl 114/77 R, ll4/72, ll4/43.5 [51] Int. Cl B63b 3/08[58] Field of Search 114/77, 72, 65 R, 56, 43.5,

[56] References Cited UNITED STATES PATENTS LAnglois 114/77 A 1,141,7556/1915 Basile 114/77 A 3,417,721 12/1968 Vienna 114/435 FOREIGN PATENTSOR APPLICATIONS 1,540,995 7/1967 France 114/435 Primary Examiner-TrygveM. Blix Assistant ExaminerSherman D. Basinger Attorney, Agent, orFirm-Brisebois & Kruger [5 7 ABSTRACT A vessel comprises a skeleton partcarrying propulsion and steering means and comprising a bow section anda stern section connected by a spine and a plurality of containerportions engageable with the skeleton part intermediate the bow and stemsections and laterally of the spine, the container portions when engagedwith the skeleton part defining therewith the exterior shape of thevessel hull.

10 Claims, 8 Drawing Figures VESSEL WITH REMOVABLE SECTIONS,

This invention is concerned with improvements in and relating tovessels.

The size of cargo carrying vessels and in particular tankers, hereaftercalled crude carriers, has increased very considerably in recent yearsto vessels of the order of 250,000 to 350,000 tons.

Apart from structural considerations, one of the principal difficultiesin enlarging the size of crude carriers to the region of 1,000,000 tonsand over is the time consumed in cargo handling for a vessel of thissize by the use of conventional pumping methods. In addition, very largecrude carriers, which will be referred to as VLCCs, of the proposed sizeare physically too large for the shipyards and docking facilitiespresently provided in most parts of the world.

According to the present invention there is provided a vessel comprisinga skeleton part carrying propulsion and steering means, a plurality ofcontainer portions, and means for releasably engaging the containerportions with the skeleton part, the container portions when engagedwith the skeleton part defining therewith the exterior hull shape of thevessel.

Such a vessel may be used for various cargoes, such as solids, liquidsand gases, but is particularly intended as a crude carrier.

Further features and advantages of the present invention will appearfrom the following description of some embodiments, given by way ofexample only, reference being had to the accompanying drawings, inwhich:

FIG. 1 is a perspective view of the skeleton part of a vessel and acargo container detached therefrom;

FIG. 2 is a perspective view of a cargo container;

FIG. 3 is a plan view of a part of the skeleton part and of a container;

FIG. 4 is a perspective view of a vessel in process of attachment of aloaded cargo container;

FIG. 5 is an enlarged perspective view of a part of the skeleton partand a part of a cargo container;

FIGS. 6 & 7 are a plan and a partial vertical section through a cargocontainer part showing the oil pumps and power units for theiroperation, and

FIG. 8 is a plan view of two cargo container parts being towed by twotugs.

The vessel comprises a skeleton part 1 having a bow section 2, a spine3, an intermediate or midships section 4 and a stern section 5. Thisskeleton part houses the power unit, steering gear, main services,navigation gear, accomodation, ballast tanks, bunkers, etc.

The skeleton part defines a number of berths 6 in each of which a cargocontainer part or caisson 7 can be received. Means provided to engagethe caissons 7 with the skeleton part 1 comprise lugs 8 on the skeletonpart having tongues 9, the lugs being engageable in recesses 10 in thecaissons wherein the tongues 9 can engage in cavities 11 in the caissonsupon relative vertical movement of each caisson 7 and the skeleton part1.

In FIG. 1 four berths 6 are shown in the skeleton part l but six or moremay be provided.

The vessel of FIG. 1 is envisaged as over 2,000 ft. in length and havingfour caissons of 250,000 tons capacity each. Where more than fourcaissons are envisaged, they are of lesser capacity to achieve a liketotal.

In operating the vessel, the caissons are loaded by conventional meansat the cargo loading point. For liquid cargoes their manifolds areconnected by means of flexible pipes and couplings, or by connection torigid metal flow booms.

The loaded caissons 7 are moved to the location of the skeleton partwhich generally does not enter the harbour or oil dock facility, bymeans of tugs, FIG. 8 showing an example of two caissons 7 being movedby two tugs 12, to be further described. The caissons 7 are moved intothe berths 6 in the skeleton part, the sequence being immaterial as thecaissons are identical. The caissons, being fully loaded, have a deepdraught. When all caissons are provisionally in situ with the lugs 8aligned with recesses 10, the skeleton part is ballasted. As it islowered, the tongues 9 which have a wedge section, start to engage inthe cavities Ill which are wedge-shaped as shown in FIG. 5. The tongues9 guide the caissons 7 through the ultimate stages of alignment in theberths 6 in the skeleton part 1. When the caissons 7 are in positionwith their decks flush with the deck of the skeleton part, they arepositively locked thereto by locking means shown diagrammatically at 15,which are carried by the skeleton part on, for example, stems 16 whichare hydraulically movable vertically, The locking means may have lugsengageable in recesses in the caissons and may provide locking in bothdirections of movement of a caisson 7 relative to the skeleton part 1.They can also include a facility to adjust the position of a caissonwhen one of its ends gets out of height alignment during the attachmentprocess by providing a vertical thrust component on the caisson 7relative to the skeleton part 1 or this component may be provided bypower operated pads carried by the skeleton part and bearable onsuitable surfaces of the caisson 7.

Instead of attaching all caissons simultaneously, as described above,one or several caissons 7 can be attached at a time. If the operationhas to be done repeatedly, the skeleton part I is ballasted anddeballasted repeatedly as required. If, for example, a single caisson atthe bow end is to be attached, the skeleton part ll may be ballasteddown by the stem. The resulting misalignment in the horizontal plane iscorrected in the attachment process by the wedge shaped tongues 9and-slots 11 which have a gradually increasing cone action which leversthe caisson into position, and by the pads. The inevitable bumps againstthe hull of the skeleton part are taken up by a wooden or resilientsurface layer 14 (FIG. 5) on the skeleton part 1.

On completion of the loading operation, deck pipe lines on the caissonsare coupled to those on the deck of the skeleton part, connecting alltanks to the ships pumping system as in a conventional tanker. The shipcan therefore be ballasted as required by transferring cargo from onetank to another.

It is of course desirable for all caissons 7 to be attachedsimultaneously because this saves the maximum amount of time. Whetherthis can be done depends on the availability of the number of tugsrequired for simultaneous operation, on the tranquillity of the sea, andon the skill of the various operators.

Discharge of the cargo is effected in a like manner. The locking means15 are released and the skeleton part 1 is de-ballasted until thecaissons are free of the tongues 9 so that the caissons can be towedaway. It is likewise possible to detach one or several caissons only, byanchoring the caissons which are not to be de-. tached, to the skeletonpart, with sufficient freedom to allow for the rise of the skeleton partduring deballasting. These caissons thus remain semicaptive in such aposition that they lock again automatically when the skeleton part isre-ballasted.

Caissons which are delivered for discharge are at once replaced by emptycaissons, if there is insufficient time to discharge and return thecaissons. Advantageously, sufficient numbers of caissons are providedfor the necessary number of caissons to be ready at the discharging orloading place, to effect the exchange without waiting for the loadingand/or discharging charging operation to be completed. As crude oiltraffic on a large scale operates generally between one loading facilityin the East and one or several refinery docks in Europe, appropriatearrangements can be made. In operation, loaded caissons are provided atone end and empty caissons at the other, so that the loading anddischarge time does not cause standstill of the skeleton part. It isexpected that this system will result in a faster turnaround of thevessel which will produce important operational economies.

Referring again to FIG. 8, this shows a special method which could beused to propel two caissons by two tugs, employing special tackle in theform of bridles. In this configuration, caissons can be transportedquite conveniently over long distances. The configuration would be usedprimarily for the purpose of trans porting caissons from one loading ordischarge point to another, for operational purposes.

Positioning of the caissons in the last stage, that is after the tugshave pushed the caisson into approximate position inside the berth, iseffected by ropes and winches. The skeleton part is provided with twodeck winches (not shown) at every berth which serve to pull the caissonclose to the skeleton part and to regulate its longitudinal position. Ifthe operation is to be performed at the optimum level of efficiency(simultaneously for all caissons), close co-operation between all winchoperators (who would also control the hydraulic pads) is required. Tofacilitate this process, computerized controls for the pads, winches andthe ballasting pumps may be used and including sensing elements such aselectric eye cells, which continuously compare the deck levels of theskeleton part with those of each caisson, and proximity feelers whichindicate whether both ends of each caisson are within tongueengagementdistance. At the appropriate moment, and after all adjustments at thewinches have been performed under computer control, the skeleton part islowered by ballasting. During this stage, it is the task of the winchoperators (or of the computer) to take up the slack as the distancebetween the caisson decks and the skeleton part deck diminishes.

An elaborate computer is not required but a simple control system whichwill prevent the supervisor on the bridge lowering the ship until allwinch operators report that all caissons are in correct pre-lockingalignment.

It will be noted that the berths have tongues 9 on all three sides. Thetransversely positioned tongues 9 have the secondary purpose oftransferring those stresses which are normally taken up by the hull of aship, to the hull of the caisson.

The caisson system changes the basic construction of the ship radicallyfrom that of conventional tankers. At present, VLCCs are constructed asall ships have been in the past. Stresses are primarily carried by amultitude of girders (keelsons) in the bottom of the ship. Tankers havefewer interior frames and stringers than other types of ships becausetheir interior is pre-eminently empty of all structures, except for thebulkheads which divide the tanks. In enlarging tankers from theestablished size of 75,000 to over 200,000 tons (the present VLCCs), thelongitudinal stiffening of the structure became of paramount importance.During trial runs, this part of the structure is generally checked bystrain gauges.

The skeleton part of the ship described herein has a comparativelynarrow spine or centre section which could accommodate only acomparatively small number of conventional girders. On the other hand,the elongated and narrow centre section lends itself very well to theaccommodation of a substantial box girder with cross braces which willhave greater stability than the ordinary profiled girders. The stresscalculations for this type of box girder are more akin to structuralengineering than to naval architecture, and the indications are thatthis form of rectangular backbone will furnish the rigidity which isrequired for a vessel of the proposed length which may easily bridge anumber of wave troughs and may be temporarily less supported on severalpoints of the structure. A floating bridge girder may be used, thenarrow edge of which forms the keel, supported by a rudimentary bow andstem section. The latter contains all machinery (as in conventionaltankers), and the backbone accommodates all auxiliary ballast tanks,bunkers and slop tanks, and also processing facilities for the dirtyballast. V

The skeleton part alone of the ship is designed to be seaworthy in theabsence of one or several caissons, but its performance is considerablyimpaired by increased drag. In closed configuration (with all thecaissons in situ), the ship should perform as well as a conventionalship, although there will be small gaps between the caissons and theskeleton part. These gaps, which set up resistance, may be avoided orclosed by overlapping plates or elastic seals.

It will be evident that the above described system can also be appliedto ordinary cargo carriers and not only to tankers. In this application,the containerization containers themselves form part of the ship.

Finally, the ship has certain advantages in avoiding pollution. One ofthe principal objections to increases in the present size of tankers isthe enormous increase in comtamination which would occur if the shipmeets with an accident. In a caisson-type ship, this danger is minimizedbecause those caissons which are not affected by the accident can be setloose and can be subsequently recaptured and towed away. In allprobability, in a serious accident oil pollution would be restricted tothe contents of one caisson.

Therefore, this ship, in case of collision, stranding or fire, does notpresent the hazard to the entire ship and /or cargo as does theconventional ship and therefore will reflect favourably on insurancepremiums.

This ship allows quick turn around because cargoes can be left at oneport while the remaining cargo is taken to the next port of discharge.This isparticularly important in the case of cryogenic cargoes.

This ship may reduce the port charges due to reduction in gross tonnage.

This ship can, if desired, eliminate the discharging of cargoes by theships crew. Instead shore crews can handle the discharging of cargoes.

This ship allows the drydocking and repairs of the hull to be done withthe minimum of delay to the ship.

We claim:

1. A vessel comprising:

a. a skeleton part carrying propulsion and steering means, comprising abow section and a stern section connected by a spine and defining aplurality of recesses between the bow and stem sections and said spine,each said recess being open at its top and bottom and laterally of saidvessel;

b. a plurality of individually floatable container portions;

c. means for releasably engaging said container portions in saidrecesses intermediate said bow and stem sections and laterally of saidspine, said means comprising downwardly extending stationary tonguemeans on said skeleton part and upwardly opening cavity means on saidcontainer portions, said tongue means being engageable in said cavitymeans by relative vertical movement of said skeleton part and saidcontainer portions; and

d. means for controlling the buoyancy of said skeleton part;

and wherein said container portions, when engaged with said skeletonpart, define therewith the exterior hull surface of the vessel.

2. A vessel according to claim 1 including an intermediate sectionextending laterally from said spine intermediate said bow and sternsections and defining therewith berths for said container portionsdefined on three sides by said skeleton part, said releasable engagingmeans being positioned to couple a said container portion to saidskeleton part on the three sides of a said berth.

3. A vessel comprising:

a. a skeleton part carrying propulsion and steering means and defining aplurality of recesses each of which is open at its top and bottom andlaterally of the vessel;

b. a plurality of individually floatable container portions; and c.means for releasably engaging said container portions in said recessdefined by said skeleton part;

said container portions when engaged with said skeleton part definingtherewith the exterior hull shape of the vessel.

4. A vessel according to claim 3 wherein said skeleton part comprises abow section and a stern section connected by a spine, said containerportions being releasably engageable with the skeleton part between thebow and stem sections and laterally of the spine.

5. A vessel according to claim 4 including an intermediate sectionextending laterally from said spine intermediate said bow and stemsections and defining therewith berths for said container portionsdefined on three sides by said skeleton part, said releasable engagingmeans being positioned to couple a said container portion to saidskeleton part on the three sides of a said berth.

6. A vessel according to claim 3 wherein said releasable engaging meanscomprise stationary tongue means and cavity means on said skeleton partand each said container portion.

7. A vessel according to claim 6 wherein said tongue and cavity meansare interengageable by relative vertical movement.

8. A vessel according to claim 7 wherein said tongue and cavity meansare wedge-shaped in the vertical direction to facilitateinter-engagement.

9. A vessel according to claim 8 wherein each said tongue means extendsdownwardly from a lug mounted on said skeleton part and each said cavitymeans opens upwardly into a recess in a said container portion in whichsaid lug is positioned when said releasable engaging means are engaged.

10. A vessel according to claim 3 wherein said skeleton part is providedwith means operable to control the buoyancy thereof.

1. A vessel comprising: a. a skeleton part carrying propulsion andsteering means, comprising a bow section and a stern section connectedby a spine and defining a plurality of recesses between the bow andstern sections and said spine, each said recess being open at its topand bottom and laterally of said vessel; b. a plurality of individuallyfloatable container portions; c. means for releasably engaging saidcontainer portions in said recesses intermediate said bow and sternsections and laterally of said spine, said means comprising downwardlyextending stationary tongue means on said skeleton part and upwardlyopening cavity means on said container portions, said tongue means beingengageable in said cavity means by relative vertical movement of saidskeleton part and said container portions; and d. means for controllingthe buoyancy of said skeleton part; and wherein said container poRtions,when engaged with said skeleton part, define therewith the exterior hullsurface of the vessel.
 2. A vessel according to claim 1 including anintermediate section extending laterally from said spine intermediatesaid bow and stern sections and defining therewith berths for saidcontainer portions defined on three sides by said skeleton part, saidreleasable engaging means being positioned to couple a said containerportion to said skeleton part on the three sides of a said berth.
 3. Avessel comprising: a. a skeleton part carrying propulsion and steeringmeans and defining a plurality of recesses each of which is open at itstop and bottom and laterally of the vessel; b. a plurality ofindividually floatable container portions; and c. means for releasablyengaging said container portions in said recess defined by said skeletonpart; said container portions when engaged with said skeleton partdefining therewith the exterior hull shape of the vessel.
 4. A vesselaccording to claim 3 wherein said skeleton part comprises a bow sectionand a stern section connected by a spine, said container portions beingreleasably engageable with the skeleton part between the bow and sternsections and laterally of the spine.
 5. A vessel according to claim 4including an intermediate section extending laterally from said spineintermediate said bow and stern sections and defining therewith berthsfor said container portions defined on three sides by said skeletonpart, said releasable engaging means being positioned to couple a saidcontainer portion to said skeleton part on the three sides of a saidberth.
 6. A vessel according to claim 3 wherein said releasable engagingmeans comprise stationary tongue means and cavity means on said skeletonpart and each said container portion.
 7. A vessel according to claim 6wherein said tongue and cavity means are interengageable by relativevertical movement.
 8. A vessel according to claim 7 wherein said tongueand cavity means are wedge-shaped in the vertical direction tofacilitate interengagement.
 9. A vessel according to claim 8 whereineach said tongue means extends downwardly from a lug mounted on saidskeleton part and each said cavity means opens upwardly into a recess ina said container portion in which said lug is positioned when saidreleasable engaging means are engaged.
 10. A vessel according to claim 3wherein said skeleton part is provided with means operable to controlthe buoyancy thereof.